微生物学技术

Gene transcription is a dynamic process in which the desired amount of an mRNA is obtained by the equilibrium between its transcription (TR) and degradation (DR) rates. The control mechanism at the RNA polymerase level primarily causes changes in TR. Despite their importance, TRs have been rar ...

Turnover of mRNA is an important level of gene regulation. Individual mRNAs have different intrinsic stabilities. Moreover, mRNA stability changes dynamically with conditions such as hormonal stimulation or cellular stress. While accurate methods exist to measure the half-life ...

Over the past decade, researchers have recognized the need to study biological systems as integrated systems. While the reductionist approaches of the past century have made remarkable advances of our understanding of life, the next phase of understanding comes from systems-level inv ...

Genetic networks underlying many biological processes, such as vertebrate somitogenesis, cell cycle, hormonal signaling, and circadian rhythms, are characterized by oscillations in gene expression. It has been recognized that the frequency and amplitude of gene expression os ...

Although bakers and wine makers constantly select, compare, and hunt for new wild strains of Saccharomyces cerevisiae, yeast geneticists have long focused on a few “standard” strains to ensure reproducibility and easiness of experimentation. And so far, the wonderful natural resource ...

The budding yeast Kluyveromyces lactis has diverged from the Saccharomyces lineage before the whole-genome duplication and its genome sequence reveals lower redundancy of many genes. Moreover, it shows lower preference for fermentative carbon metabolism and a broader substra ...

Analysis of gene function often involves detailed studies of when a given gene is expressed or silenced. Transposon mutagenesis is a powerful tool to generate insertional mutations that provide with a selectable marker and a reporter gene that can be used to analyze the transcriptional act ...

Candida albicans is a pleiomorphic fungal pathogen whose morphogenetic plasticity has long been considered as a major virulence factor. In addition to the yeast-filament transition, C. albicans cells also have the unique ability to switch between two epigenetic phases referred to as wh ...

Methods and procedures in molecular biology used to study fungal pathogenesis have significantly improved during the last decade. In this chapter, we provide step-by-step procedures for performing genetics and biochemical studies in the human pathogenic fungal microorganism C ...

Since Helicobacter pylori was first described in 1983 (1), the study of genomic DNA has been central to the development of its microbiology and molecular genetics. For instance, DNA base composition estimation (mol% G+C) was crucial in demonstrating affinities of the microorganism to the ge ...

There are a number of techniques available for the detection and characterization of mutations that take advantage of the flexibility and power of polymerase chain reaction (PCR) (Table 1). Sequencing remains the gold standard, but it is not very efficient as a screening tool, in particular wh ...

The discovery of polymorphic DNA in Mycobacterium tuberculosis has led to several methods to differentiate climcal isolates. The most widely used method is based on the mobility of the insertion element IS6110, which is present in virtually all M tuberculosis isolates, usually in multip ...

Helicobacter pylori establishes chronic infections in the human gastric mucosa that can last for decades, and that are a major cause of gastritis and peptic ulcer disease (PUD) and a risk factor for gastric cancer. The importance of H. pylori as a human pathogen has led to major efforts to understand its ...

Certain nonconserved genotypic and phenotypic characteristics of H. pylori are associated with increased risk of peptic ulceration in the human host. These characteristics can be divided into two groups: first, those relating to vacuolating cytotoxin activity (1,2), and differen ...

An ability to distinguish individual strains of Helicobacter pylori with sensitivity and efficiency is valuable for studies of the epidemiology, population genetic structure, and evolution of this gastric pathogen. The arbitrarily primed polymerase chain reaction (AP-PCR), or ...

There is a great need to develop molecular techniques for the typing of Helicobacter pylori isolates since classical bacteriological assays, such as serotyping or lysotyping, are lacking. Such techniques would provide the microbiologist with the tools necessary to differentiate ...

Helicobacter pylori strains have been shown to display considerable heterogeneity with respect to DNA sequence. Diverse restriction fragment length polymorphism (RFLP) patterns are generated among strains by restriction endonuclease digestion of whole chromosomal DNA ( ...

Ribotyping, a method used to type strains of bacteria by analyzing the restriction enzyme digestion patterns of the ribosomal RNA (rRNA) genes, was first developed and proposed as a taxonomical tool for the identification and differentiation of bacteria by Grimont and Grimont, in 1986 (1). Si ...

Transposable elements are well-known genetic tools that enable the geneticist to generate mutations by disrupting the linear continuity of a specific gene and, consequently, affect its expression. This approach, in addition to providing an efficient way to create mutants, which are ea ...

Helicobacter pylori is an important etiological pathogen of human stomach diseases, such as gastritis, peptic ulcer, and gastric carcinoma (1). In the past few years, great progress has been made in the cloning and characterization of H. pylori genes. Success of these studies stems in part from the ...